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61 Cards in this Set
- Front
- Back
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What is continental drift?
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The movement of major land masses, "plates", over time from the supercontinent it used to be.
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What is seafloor spreading?
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Volcanic activities at the bottom of trenches which spread new seafloor outwards from the center, forcing the rest of the seafloor outwards too. This also means that the the floor furthest away is the oldest, the floor nearest to it is the closest.
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What are mid-ocean ridges?
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A divergent boundary in which seafloor spreading happens. Convergent boundaries form them when the heavier oceanic lithosphere meets the continental lithosphere, sinking the lithosphere into a trench and raising mountains on the surface.
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What are mantle plumes?
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Hot rising magma rising through the earth over long periods of time from the deep regions of the earth through convection in narrow heated plumes.
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What is volcanism?
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A general term that refers to all phenomena connected to the origin and movement of volcanic rock.
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What is the Pacific "ring of fire"?
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The worlds most concentrated site for volcanoes, it forms a rough ring around the Pacific. Over 75% of all volcanic activity is found here.
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What are anticlines/syclines?
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Anticlines and synclines are both kinds of folds: anticlines are folds that go upwards, synclines are downward folds. there are also folds that are sharp folds called overturned folds, and there are folds so sharp they break called overthrust folds.
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What are focus/epicenter, earthquakes?
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Earthquakes are vibrations in the earth produced by shockwaves from sudden displacement along a fault., or from the movement of magma or ground subsidence. The focus is where the earthquake essentially starts, and the epicenter is the area of greatest impact directly above the focus.
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What is a horst/graben?
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Horsts are structures produced between two parallel faults when both sides are down-thrown and the center mass stays the same, creating "elevation". Grabens are the opposite, where the center land has been downthrown and the two sides stay the same.
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What is isostatic rebound?
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It is the phenomenon where the lithosphere after 'sinking" under the weight of something extremely heavy, like mountains or an icecap, will once it is removed rise over thousands of years, sometimes producing earthquakes and tremors.
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What is broad scale emergence/submergence?
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Your guess.
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What is denudation?
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Denudation is a term that implies the lowering of continental surfaces through disintegration, wearing away, and removal of rock. The three types of activity are weathering: the breaking down of rock into particles, mass wasting: the short-distance downslope movement of particles, and erosion: more extensive processes, transport, and eventual deposition of particles.
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What is the distinction between a joint and a fault?
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A joint is a common feature of rocks in the lithosphere, they are cracks that result from stress. They are thin and not nearly as jagged as faults. Faults are breaks in bedrock along where there is displacement of the walls of the crack. They are rare, but can go for hundreds of kilometers.
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What is exfoliation?
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The process by which curved layers are peeled off bedrock, leaving the area smooth. It is done through what is thought to be pressure release, or expansion of the rock.
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What is the single most important mechanical weathering agent?
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Frost wedging, due to the extent that water is present in and affects our world.
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Where is chemical weathering most effective?
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Warm and moist climates with a large exposed surface area.
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What is hydrolysis?
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Hydrolosis is the process of mixing water with another substance to produce something that is softer and usually weaker. In rocks this shows up by making things such as softer soil.
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What does chemical weathering require?
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Moisture, exposed surface area, and temperature.
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What is oxidation?
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The process under which oxygen atoms combine with various metallic elements to form different substances, essentially breaking up the metal.
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What is a slump?
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A form of mass wasting which involves slope failure in a form that makes it so that it not only moves downward but rotates outward similar to rotating half of an orb like a swing, making the lower portion go up and the upper portion go down.
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What is soil creep?
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A phenomenon that causes a very gradual downhill movement of soil and regolith so slow it can only be recognized by indirect evidence. It involves the freezing and thawing of soil, causing it to fall a bit further each time it thaws after it has already gained minuscule height from the freezing of the soil. causing it's mass to bulge out a bit from the expansion of the ice.
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What is solifluction?
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A kind of creep that happens when water thaws on the ground, but it can't soak into the ground because of the permafrost underneath it, so it saturates the soil and causes it to sag downslope, leaving a visible pattern.
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Where are interfluves found?
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Interfluves, the word coming from a latin combination of the words "between" and "rivers", is supposed to be anywhere between valleys where flowing water would be, from mountains to just anywhere in between valleys or not a part of them.
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What is the suspended load?
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Suspended load are the fine particles such as clay that are almost always suspended in water, never touching the bottom, taking sometimes as much as a year to get to the bottom even in still water.
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What is the bed load?
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Bed load are the large rock fragments on the bottom of the river that move along the bottom in jumps or bounces.
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What is the dissolved load?
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Dissolved load are the minerals like salt that are absorbed and dissolved into the water and carried with it in solution.
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What is a radial drainage pattern?
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When streams descend from some sort of concentric uplift, such as an isolated volcano.
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What is an intermittent stream?
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Intermittent streams are rivers that only exist during the rainy parts of the year, they are seasonal.
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What is base level?
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The lowest level a valley can be weathered by the river that formed it, after which the valley will become wider instead of deeper.
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What are aggraded/degraded streams?
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Aggraded streams are the accumulation of alluvium on the bottom of a river in response to its decreased flow, degraded being the opposite.
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What is rejuvenation?
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Rejuvenation in this case refers to when streams are "rejuvenated" by tectonic plate mass being uplifted, causing the streams to flow faster through an increase in gradient.
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What is the geomorphic cycle?
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The cycle by which flat land surface is lifted, incised, and then denuded back to where it was. This results in rising land during it's "youth", the formation of streams, valleys and mountains during "maturity", and then it's deflation in it's "old age", after which it must be rejuvenated.
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Where will stream erosion likely occur?
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In areas with running water, sun absorption, rough waters, solution, and abrasion.
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What is the single most important agent of landscape formation?
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Running water, which include rainfall, erosion by rain splash, sheet wash, rilling, and streamflow. Surface water includes exotic streams, ephemeral streams, desert lakes which sometimes turn dry, becoming playas, or if there is lots of salt deposition salinas. Saline lakes are those in which salt deposition is high and is common in deserts due to the high rate of evaporation.
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What is desert varnish?
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A feature present in Reg type deserts, reg arabic for stone, Reg deserts are have a large amount of gravel, pebbles, and/or boulders covering the area, the sand and dust having been removed by wind and water. Desert varnish is what happens when bacteria coat rocks with a dark shiny coating of iron and manganese oxides, it covers the surrounding rubble and is a biochemical reaction.
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What are the causes of desertification?
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Overgrazing, farming of average land, destruction of plants in dry regions, and incorrect irrigation in arid regions causing build ups of salt in the soil.
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What is a salina?
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Dried up lakes that contained lots of built up salt due to high evaporation rates.
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What is the piedmont?
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The zone at the foot of a mountain range, and in deserts is a prominent area of fluvial deposition, they are often found more prominently found on flatter portions of deserts.
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What is deflation?
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It is an Aeolian erosion process, aeolus being the greek god of the winds, in which loose particles are shifted either by being blown in the air or along the ground, it can also form a blowout, which are hollows formed in landforms caused by when wind blows out the fine material from it to form a depression.
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What are the aeolian processes?
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They are Aeolan erosion, which includes deflation and abrasion, Aeolan transportation, the transport of particles in wind, and Aeolian deposition, which forms sand dunes, which include barchans, transverse dunes, seifs, star dunes, coastal dunes, and loess.
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What is the principal component of sand dunes?
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The main component is uniform grains of quartz.
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What is loess?
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Wind deposited silt that is fine grained, calcareous, and usually buff colored. It has great vertical durability, which results in its fine grain size, high porosity, and vertical joint like cleavage planes.
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What is an alluvial fan?
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A landform made at the mouth of a canyon when steams become choked and overflow, seeking to create new channels and thus fan out.
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What is a mesa?
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A flat-topped surface, in this case land forms made by the fact that the land forms were composed of layers, and the top ones did not resist the weathering, thus creating the flat surface.
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What was the maximum extent of Pleistocene glaciations?
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At it's maximum extent, ice covered one-third of the earth, nearly 47,000,000 square kilometers
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What was the approximate sea level during the Pleistocene?
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It was about 130 meters (430 feet) lower than what it is today.
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What are outlet glaciers?
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Parts on the outer margins of continental ice sheets, land based large ice coatings on the earth that extent long distances and are very deep. Outlet glaciers are tongues of ice that extend between the hills to the sea.
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What is neve?
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It is the accumulation of snow as it becomes denser until it is half the density of water, becoming true neve.
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What is the primary cause of down slope glacial movement?
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Glacial stress, due to the pressure it is under, starts to melt and creates fluid with which it slides down slopes. This become the plastic flow of out and basal slip.
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What is a glacial striation?
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Fine parallel indentations left in bedrock by Glacial abrasion.
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What is a glacial erratic?
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Oversized boulders deposited by glaciers as they travel.
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What is a kettle?
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When ice falls off a glacier as it leaves but the ice becomes buried beneath the glacial drift, so when the ice melts it leaves an irregular depression.
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What is a cirque?
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The broad amphitheater indentation hollowed out by the creation of glaciers at their origins.
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What is a horn?
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The sharp peak formed when several cirque intersect, aka when several glaciers are created together this is the result in the land surrounding in the mountains.
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What is a medial moraine?
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When two lateral moraines combine together to form one medial moraine between the two glaciers, a tributary glacier and a trunk glacier.
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What are shield volcanoes?
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There are shield volcanoes, which are wide and low-lying. They can be quite tall, but they are never steep sided. They are made of multiple layers of solidified lava flows, usually basaltic, and make quiet eruptions of fluid lava.
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What are composite volcanoes?
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Steep tall symmetrical volcanoes that erupt violently with higher silicate intermediate lavas such as andesite. Its made by layers of ejected pyroclastics (cinders and ashes) and stick together extremely well.
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What are Lava Dome volcanoes?
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Bulging domeshaped volcanoes that have extremely thick and pasty lava, making it form the way it does because it will not travel far.
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What are Cinder Cone volcanoes?
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Small cone peaked volcanoes that usually have basaltic magma. They are the smallest type of volcano and they usually consist mostly of pyroclastic material.
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What is a Caldera?
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A volcano which explodes and/or collapses, creating a huge basin-shaped depression.
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What are the types of volcanoes?
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Shield, composite, lava domes, and cinder cones.
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